Free radicals can rapidly and irreversibly oxidize various structures, including unsaturated fatty acids in vegetable oils, which affect the sensory properties. Spectrophotometry is the most widely used method for the determination of free radical scavenging activity (RSA) using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Barrier to the further use of classical analytical methods to analyse biologically active compounds in foodstuffs is that equipment requires high cost and has limited mobility. One of solutions is to replace classical methods, such as spectroscopy, with smartphonebased colorimetry. Huawei P30 Lite smartphone was used for colorimetric detection. The free radical scavenging activity (RSA) in vegetable oil was detected using an application ‘Color Picker’, with image matching algorithm for red, green, and blue (RGB) model. RSA was expressed as percentage and measured by the DPPH method. The aim of the study was to determinate the total free radical scavenging activity with smartphone-based colorimetry. For the data comparison and accuracy spectrophotometer as analytical optical instrument was used. Eleven vegetable oils: sea buckthorn, sunflower, rice, macadamia nut, hemp, corn, grape, linseed, rapeseed, olive and milk thistle oils were selected for analysis. The best results with no significant differences (p is greater than 0.05) compared to smartphone-based colorimetry from spectrophotometry were determined using RG values. The poor results were detected by using B value (p is less than 0.05) and were not suitable for determination of RSA. Smartphone-based colorimetry can be used in the determination of the RSA in vegetable oils.

Fermentation of milk with probiotics and prebiotics has been shown to increase the concentration of B group vitamins in fermented milk products. The task of the study was to investigate the influence of prebiotics on the increasing of thiamin and riboflavin concentrations in milk during fermentation by Bifidobacterium lactis. Lactulose (Duphilac, Netherlands) and inulin (Raftiline, Belgium) were added (1, 2, 3, 4 and 5%) into 100 g of milk. The milk samples were inoculated with Bifidobacterium lactis (BB-12, Chr. Hansen, Denmark) and incubated at 38 deg C for 16 hours. The amount of thiamine and riboflavin was determined by fluorometric method. Laboratory studies have shown that the increasing of thiamin and riboflavin concentrations in milk depends on the concentration of lactulose and inulin. Data on the final thiamin and riboflavin concentrations in fermented milk indicates that increasing the lactulose concentration from 1% to 3% enhanced the production of thiamin and riboflavin. The similar data was obtained with inulin. Increasing of inulin concentration from 1% to 4% enhanced the production of vitamins thiamin and riboflavin. The present results furthermore indicate that finding optimal combination of prebiotics and probiotic pairs where the prebiotic would benefit the specific probiotic strain, e.g. during production and formulation into foods, is one of the research priority for functional foods.

Rosemary (Salvia rosmarinus) is an aromatic herb with a multitude of uses. It is both a seasoning in various dishes, and a natural remedy for several diseases mainly due to its anti-inflammatory and anti-oxidative effects. Plus, it is also used in cosmetic industry and for improving agriculture practices and helping the environment, since it may be a natural antimicrobial. It is worth noting that this plant is also grown and commercialized in Uzbekistan, thus, if added value is given to rosemary’s products, it has potential for improving living conditions and helping in the economy of local farmers and entrepreneurs. In this work, we discuss a technique for obtaining rosemary essential oil, rich in terpenes, by vacuum assisted hydrodistillation. This is a solventless environmentally friendly and safe technique that allows the obtention of an added value rosemary product where terpenes, compounds responsible for most of rosemary’s properties, are the most abundant. Two samples of locally acquired rosemary were sourced, essential oil was extracted, and characterization was then performed by Solid Phase Micro Extraction (SPME) and Gas Chromatography – Mass Spectrometry (GC-MS). As a comparison, a direct injection of a dilution of one of the essential oil samples was also performed. It was concluded that samples of essential oil obtained from both sources were entirely composed of terpenes or terpene derivatives. Besides, SPME was a superior method when compared to direct injection, since a larger number of volatiles was able to be identified.